南极大磷虾声学调查数据噪声处理与资源评估

在中国第28次南极科学考察期间,利用“雪龙号”科考船载SIMRAD EK500（38kHz）科学渔探仪对南极半岛附近海域的南极大磷虾资源量进行了调查。原始声学数据经过信噪比估算和背景噪声剔除数据后处理方法剔除背景噪声以及手动剔除表面混响、海底反射和坏数据之后,在200 m以浅水层中,以1n mile间隔进行积分,并应用Matlab软件编程对积分结果进行后处理,得出调查海域中南极大磷虾的资源分布情况。结果表明：（1）“雪龙号”的平均噪声功率值为-146.47dB re 1W;(2)空白水体的噪声平均剔除百分比为88.3%;（3）调查区域内的南极大磷虾平均密度为27.30 g·m^-2（62.95 ind·m^-2）。     

生活方式型移民研究综述

在经济比较发达以及后现代社会带来个人主体性增强的背景下,以寻找更好的生活方式的迁移——“生活方式型移民”成为一种重要的人口流动类型,并受到西方学者的高度关注。在中国,生活方式型移民开始萌芽,然而研究较少,目前主要集中在对生活方式型旅游企业主移民研究;西方的研究则涉及退休移民、生活方式型企业主移民等多种类型,但尚未形成完整的研究体系,对于生活方式型移民概念界定及其类型划分较为杂乱。为此,本文从现有文献出发,试图对这类移民的研究内容进行介绍、探讨、厘清和评析,首先确定“生活方式型移民”的概念框架,根据生产和消费在时间和空间上的结合状态将生活方式型移民划分为三种类型,并从社会交往、生活状态、旅游行为和自我认知等方面综述其迁移后的行为表现及由此产生的影响,希望借此促进中国学者对生活方式型移民的关注。     

Time-domain electromagnetic migration in the solution of inverse problems

Time-domain electromagnetic (TDEM) migration is based on downward extrapolation of the observed field in reverse time. In fact, the migrated EM field is the solution of the boundary-value problem for the adjoint Maxwell's equations. The important question is how this imaging technique can be related to the solution of the geoelectrical inverse problem. In this paper we introduce a new formulation of the inverse problem, based on the minimization of the residual-field energy flow through the surface or profile of observations. We demonstrate that TDEM migration can be interpreted as the first step in the solution of this specially formulated TDEM inverse problem. However, in many practical situations this first step produces a very efficient approximation to the geoelectrical model, which makes electromagnetic migration so attractive for practical applications. We demonstrate the effectiveness of this approach in inverting synthetic and practical TDEM data.     

旅游移民研究体系及方法初探

近年来,一种基于大众旅游的新人口迁移现象——旅游移民受到西方学者的高度关注。在我国,旅游移民现象已经出现,但研究较少。西方学者对旅游移民的研究较为注重实证分析,缺少对旅游移民概念及其研究体系的准确界定。笔者在对国外相关文献分析和已有实证研究基础上,对旅游移民的概念体系进行了界定,把旅游移民划分为旅游劳工移民和旅游消费移民两大类,确定旅游移民研究的三大方向为行为理论研究、发生论研究和社会影响研究,并对每个研究方向的主要内容进行了明确,构建出旅游移民的研究体系。同时,提出了旅游移民研究可借用的相关移民动力学、行为学、社会学等理论,以及质性研究、量化研究、比较研究、长期站点监测和个案研究等具体研究方法和需要注意的方面,对我国旅游移民研究进行了理论和方法的初步探讨。     

The feminization of migration in the Pearl River Delta

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空气质量对中国人口迁移的影响

随着中国流动人口群体构成和迁移模式的持续变化,空气质量等舒适性要素逐渐成为塑造人口迁移空间格局的重要因素.基于2000年以来的人口普查和抽样调查数据,本文探讨了空气质量对人口迁移影响的总体特征、变动趋势和作用模式.研究发现,空气质量已逐渐成为影响中国人口迁移格局的重要因素,且主要表现为推力作用.空气质量直接关系到人口迁...     

A proportional odds model of human mobility and migration patterns

The modelling of human mobility and migration patterns has received much attention due to its substantial importance. Despite long-term efforts, we still lack a modelling framework that captures mobility patterns and further obtains a prospective view of movement trends with regards to diverse impacting factors. Here, we propose a proportional odds model of human mobility and migration (POM-HM) that takes a probabilistic approach to model human movements. Our model is based on the migration probability with a log-logistic distribution under the proportional odds assumption. Explanatory variables are introduced into the model by re-parameterizing the probability distribution function. The two resultant functions, namely, the migration strength and cumulative hazard, are used to estimate regional differences among travel fluxes and their tendencies. The performance of the POM-HM in terms of its validity and accuracy is examined and compared with the gravity model and the radiation model. The probability-based modelling framework enables us to investigate regional variations in migrant fluxes consequently further predict potential future patterns. In short, our modelling approach captures the probabilistic nature of human mobility and migration and furthers our understanding of both the spatiotemporal patterns of population movements and the impacts of various driving forces.     

中国省际高技能人才迁移的时空演化机制

高技能人才迁移是推进新型城镇化建设的重要议题,也是影响地区创新产出和高质量发展的关键要素。针对人才迁移数据中蕴含的零膨胀和网络自相关特性,本文将特征向量空间滤波（ESF）技术和“两阶段”Hurdle模型结合,构建空间Hurdle引力模型,结合2000—2015年中国省际高技能人才迁移面板数据,研究人才迁移的时空演化格局和驱动机制。研究结论显示：① 2000—2015年人才迁移的跨省迁移比例先升后降;人才迁移表征出集聚格局,维系了其空间分布的不均衡性;随时间推移,人才迁移格局呈现分散趋势,人才空间分布集聚性下降;人才迁移和空间分布均呈现出持续显著的网络与空间自相关性特征。② 引力因素（人口规模、空间距离）、地区经济和科技发展水平（工资、科教投入）、自然舒适度（平均温差、空气质量）、城市舒适度（医疗及教育公共服务、城市绿化）以及其他因素（社会网络、生活成本、人口密度）共同驱动了跨世纪以来中国省际人才迁移过程。③ 人才迁移可被看作一个“两阶段”过程,影响其迁移概率和迁移规模的因素呈现一定差异。④ 经济增速、科教投入、自然舒适度和基础公共服务对人才迁移的影响随时间增强,而工资和城市绿化的影响随时间减弱。本文的研究结论为地区人才治理及实现地区均衡发展提供政策参考。     

Population migration across the Qinghai-Tibet Plateau: Spatiotemporal patterns and driving factors

Developing a comprehensive understanding of inter-city interactions is crucial for regional planning.We therefore examined spatiotemporal patterns of population migration across the Qinghai-Tibet Plateau(QTP)using migration big data from Tencent for the period between 2015 and 2019.We initially used decomposition and breakpoint detection methods to examine time-series migration data and to identify the two seasons with the strongest and weakest population migration levels,between June 18th and August 18th and between Oc-tober 8th and February 15th,respectively.Population migration within the former period was 2.03 times that seen in the latter.We then used a variety of network analysis methods to examine population flow directions as well as the importance of each individual city in migra-tion.The two capital cities on the QTP,Lhasa and Xining,form centers for population migra-tion and are also transfer hubs through which migrants from other cities off the plateau enter and leave this region.Data show that these two cities contribute more than 35％of total population migration.The majority of migrants tend to move within the province,particularly during the weakest migration season.We also utilized interactive relationship force and ra-diation models to examine the interaction strength and the radiating energy of each individual city.Results show that Lhasa and Xining exhibit the strongest interactions with other cities and have the largest radiating energies.Indeed,the radiating energy of the QTP cities cor-relates with their gross domestic product(GDP)(Pearson correlation coefficient:0.754 in the weakest migration season,WMS versus 0.737 in the strongest migration season,SMS),while changes in radiating energy correlate with the tourism-related revenue(Pearson correlation coefficient:0.685).These outcomes suggest that level of economic development and level of tourism are the two most important factors driving the QTP population migration.The results of this analysis provide critical clarification guidance regarding huge QTP development dif-ferences.     

Barchans of Minqin: quantifying migration rate of a barchan

The migration speed of a typical barchan on the border of Minqin oasis,Gansu Province,northwestern China,was estimated by means of two methods.One is on the basis of a simple physical model and short-term field measurements.The other comes from the combination of the barchan internal structure detected by ground-penetrating radar and optical/radiocarbon dating techniques.The upper limit of migration speed given by conventional C-14 dating is 3.42 m/yr.The optically stimulated luminescence dating indicates that the time-average migration speed of the studied barchan was 1.78 m/yr in 28 years prior to 2007.The physical estimation further suggests that the annual migration speed has increased in recent years.     

Pacific islands in the global economy: Paradoxes of migration and culture

Predictions for the future of small islands and island states are invariably pessimistic. Poverty has increased, free trade offers limited possibilities, governance is weak and urban biased, and aid dependence has not declined despite aid fatigue. Populations are contracting from outer islands. One outcome has been increasing migration and remittances, as safety valve and diversification strategy. Selective migration and limited return migration have contributed to skill drain. Yet migration has enabled peripheries to survive through improved welfare and investment, and sustained social structures. Formal development strategies, whether international or national, emphasize 'modernity', with culture to be abhorred and ignored; yet hybridity offers possibilities for more equitable sustainable development. A combination of migration, economic diversification and cultural hybridity provides alternative development trajectories.     

环境移民国际研究态势的文献计量评价

随着人口增加和环境压力日益增大,环境移民问题已成为生态、环境以及人口学方面的研究热点。以SCIE和SSCI数据库研究论文为数据源,利用Thomson Data Analyzer(TDA)和UCINET软件对其进行数据挖掘和定量分析。结果表明:相关研究的发文量整体呈稳态增长趋势;美国及其主要机构在该领域处于领先地位。在国家和机构层面,中国及中国科学院发文量较多,且近年来研究较为活跃,但研究水平、影响力有待提高;美国、德国、英国在国际合作研究中占有重要位置,中国及其研究机构与其他国家和机构的合作研究关系较弱;研究主题主要关注生态保护、扶贫性移民、移民迁出地和安置区、移民社会学及其政策等方面。     

天津城市内部人口迁居特征及机制分析

在对天津市民问卷调查等第一手资料进行详细分析的基础上,总结出天津城市内部人口迁居的迁移性、迁移方向性、迁移距离和迁移空间类型等特征,初步分析了迁居机制及其变化,提出天津城市居住空间结构调整的相关建议。     

地缘政治视角下的跨境移民和族裔社区研究

在全球-地方频繁互动的今天,跨国/跨地方逐渐成为超高速流动的社会现实,移民与流入流出地的多元互动模糊了国与国、地方与地方之间的边界,在目的地不断重塑社会结构和空间,在物质和符号维度赋予了地方不同的意义。族裔社区不仅仅反映了不同的移民群体复杂的日常生活实践及其在空间上的互动,也将对多元化族裔空间的关注转移到社区、空间、领土政治甚至流动地缘想象,同时也将族裔社区空间纳入一个关系性的视角下。而传统上地缘政治视角对移民和族裔空间的关注相对有限。因此,本专栏主要讨论地缘政治视角下的跨境移民和族裔社区。具体而言,专栏首先回顾了地缘政治研究及其对流动性的关注和移民研究中的地缘政治面向,其次通过8篇文章讨论了不同尺度下多元的跨境移民及族裔社区营造与建构的相关研究,希冀从理论、方法以及实证研究方面对现有知识进行补充,也尝试通过探索国内外相关研究的进展,为社会和国家治理的需求服务。     

中国省际人口迁移格局演变及其对城镇化发展的影响

基于2000年和2010年人口普查数据,利用多种指标和方法研究了中国省际人口迁移的格局演变及其对城镇化的影响。研究发现：省际迁入和迁出人口在空间分布上均呈分散化态势,迁入迁出重心均向北向东偏移,迁入地由广东省“一枝独秀”向多极化演变,安徽、四川、河南、湖南成为新的四大迁出地。利用净迁移流构建的省际人口迁移网络,表现出紧凑化和均衡化趋势;迁移流仍然是从中西部地区指向东部地区,但新增加迁移流集中指向长三角、京津以及福建。综合考虑省际人口迁移强度和方向,可将全国31个地区划分为净流入型活跃区、平衡型活跃区、净流出型活跃区以及非活跃区四种类型。省际迁移改变了迁入地和迁出地的城乡人口结构,通过不同模式促进了城镇化率的提高和省际差异的缩小,对2000-2010年全国城镇化率增加的贡献占到了18.13%。